fix(extraction): a Go method carries the exportedness of its name

[danusha2345]

Standalone off main (b9ca4b7), one commit, both extraction arms. The extractor defect noted in #1731.

What

extractMethod never set isExported, so every Go method was indexed as unexported whatever the case of its name — 148 of 148 on a 42-file tree, func (w *rotatingLogWriter) Close() included — while plain functions carried the flag. codegraph-kernel/src/go.rs mirrored the omission literally (// extractMethod passes no isExported).

A method that is a top-level declaration (methodsAreTopLevel — Go is the only such extractor) now receives the extractor's isExported exactly as a function does, and go.rs sets is_exported from the same name-case rule in extract_method. Class members in other languages keep the flag unset on purpose: their reachability is the class's, and the JS/TS isExported walks the parent chain, so applying it to methods would re-mark every member of an exported class and diverge the tsjs kernel walker.

Measured

Same Go/Kotlin/JS tree, kernel rebuilt from this checkout and confirmed loaded with CODEGRAPH_KERNEL_DEBUG=1:

Go methods	base	this
exported	0	41
unexported	148	107

Close / String → exported, close → not. Functions unchanged (135 / 175). The wasm arm (CODEGRAPH_KERNEL=0) gives the same flags.

Tests

extraction.test.ts: a four-symbol Go file (Close, flush, Open, helper) asserting the flag on both methods and both functions; passes on the wasm arm and with the kernel loaded. kernel-scaffold, kernel-deep-nesting, kernel-grammar-parity: 31 passed with the rebuilt kernel.

Relationship to #1732: that PR judges Go visibility by the name's case precisely because this flag was unusable; with this in, the flag and the case agree, and #1732's rule can later read the flag.

🤖 Generated with Claude Code

[danusha2345]

Rebased onto current main (2f1a99d): head 38d2b25. Conflicts were only the CHANGELOG and the neighbouring #1729 tests in extraction.test.ts. Kernel rebuilt; the Go test passes on both arms. Once this lands, the by-name-case rule #1745 carries for Go can read the flag instead.

[danusha2345]

Rebased onto current main (b715eb6): head 18b4b30, one commit. CHANGELOG was the only conflict. Kernel rebuilt; the Go extraction tests pass on both arms (kernel and CODEGRAPH_KERNEL=0).